Alcmaeon

Alcmaeon of Croton was an early Greek medical writer and
philosopher-scientist. His exact date, his relationship to other early
Greek philosopher-scientists, and whether he was primarily a medical
writer/physician or a typical Presocratic cosmologist, are all matters
of controversy. He is likely to have written his book sometime between
500 and 450 BCE. The surviving fragments and testimonia focus
primarily on issues of physiology, psychology, and epistemology and
reveal Alcmaeon to be a thinker of considerable originality. He was
the first to identify the brain as the seat of understanding and to
distinguish understanding from perception. Alcmaeon thought that the
sensory organs were connected to the brain by channels
(poroi) and may have discovered the poroi connecting
the eyes to the brain (i.e. the optic nerve) by excising the eyeball
of an animal, although it is doubtful that he used dissection as a
standard method. He was the first to develop an argument for the
immortality of the soul. He used a political metaphor to define health
and disease: The equality (isonomia) of the opposing powers
which make up the body (e.g., the wet, the dry, the hot, the cold, the
sweet, the bitter etc.) preserves health, whereas the monarchy of any
one of them produces disease. Alcmaeon discussed a wide range of
topics in physiology including sleep, death, and the development of
the embryo. It is unclear whether he also presented a cosmology in
terms of opposing powers, but we do have some testimonia concerning
his views on astronomy. Alcmaeon had considerable impact on his
successors in the Greek philosophical tradition. Aristotle wrote a
treatise responding to him, Plato may have been influenced by his
argument for the immortality of the soul, and both Plato and Philolaus
accepted his view that the brain is the seat of intelligence.

Alcmaeon, son of Peirithous (otherwise unknown), lived in the Greek
city of Croton on the instep of the boot of Italy. Diogenes Laertius,
in his brief life of Alcmaeon (VIII. 83), asserts that he wrote mostly
on medical matters. There is, however, little direct evidence for his
work as a practicing physician. Later writers in the medical
tradition, such as Galen (DK A2), treat him as a philosopher-scientist
rather than as a physician, so that some scholars (Mansfeld 1975; cf.
Perilli 2001 for a critique) have concluded that he was not a doctor
at all but rather a typical Presocratic physiologos (writer
on nature). The majority of scholars, however, because of
Diogenes’ remark and because of the focus on the functioning of
the human body in the testimonia and fragments, refer to Alcmaeon as a
physician-philosopher. The historian Herodotus tells us that, in the
second half of the sixth century, the physicians of Croton were the
best in the Greek world (III. 131) and recounts in some detail the
activities of the most prominent Crotoniate physician of the time,
Democedes (III. 125–138). Thus, whether a practicing physician
or not, Alcmaeon undoubtedly owes some of his interest in human
physiology and psychology to the medical tradition in Croton. In the
fifth century, it is difficult to draw clear lines between the work of
a medical writer/physician and a philosopher/scientist. Presocratic
cosmologies of this period devoted some attention to questions of
human physiology and medicine, and conversely the early treatises in
the Hippocratic corpus often paid some attention to cosmology (see
Aristotle, Resp. 480b23 ff.). The earliest Presocratic
cosmologies in Ionia (e.g., those of Anaximander and Amaximenes) did
not deal with physiology, and it is possible that the new interest in
physiology in cosmologies of the fifth century (e.g., those of
Empedocles and Anaxagoras) was due to the influence of Alcmaeon (Zhmud
2012a, 366; 2014, 100).

Croton is also famous as the center of Pythagoras’ activity from
ca. 530, when he left Samos. Alcmaeon addressed his book to three men
who may have been Pythagoreans:

Alcmaeon of Croton, son of Peirithous, said the following to Brotinus,
Leon, and Bathyllus… (DK, B1)

We know nothing of Leon and Bathyllus, except that Iamblichus, in
On the Pythagorean Way of Life (=VP), lists a
Pythagorean named Leon from Metapontum and a Pythagorean Bathylaus
from Poseidonia (Paestum), both Greek cities of southern Italy
(VP 267). Bro(n)tinus is identified as a Pythagorean from
Croton in some places (D.L. VIII. 42; Iamb. VP 132) and from
Metapontum in others (VP 194, 267). He is either the father
or the husband of Theano, who is in turn either the wife or student of
Pythagoras. Does this “dedication” of his book to
Pythagoreans indicate that Alcmaeon himself was a Pythagorean? Even if
this is a dedication, it does not follow that Alcmaeon agreed with the
views of his addressees. Comparison with Empedocles’ address to
Pausanias suggests, moreover, that what we have is not a dedication
but an exhortation or an attempt to instruct (Vlastos 1953, 344, n.
25). Alcmaeon might be quite independent of these Pythagoreans and
trying to persuade them of his distinct point of view.

Diogenes Laertius, in his Lives of the Philosophers
(3rd century AD), includes Alcmaeon among the Pythagoreans
and says that he studied with Pythagoras (VIII. 83). Later authors
such as Iamblichus (VP 104, 267), Philoponus (De An.
p. 88), and the scholiast on Plato (Alc. 121e) also call
Alcmaeon a Pythagorean. A majority of scholars up to the middle of the
twentieth century followed this tradition. However, it is not true
that the ancient “tradition is unanimous in presenting him as a
Pythagorean” (Zhmud 2012a, 123). In fact, the majority of
ancient sources do not describe him as a Pythagorean (e.g., Clement
[DK 24A2], Galen [DK24A2], Aetius [DK 24A4, 6, 8–10, 13,
17–18], Censorinus [DK 24A13–14], and Chalcidius [DK
A10]). The best argument for regarding him as Pythagorean would be his
inclusion in Iamblichus’ catalogue of Pythagoreans at the end of
his On the Pythagorean Life, if we could be sure that all
parts of that catalogue go back to Aristoxenus in the fourth century,
since Aristoxenus is a very knowledgeable source on Pythagoreanism
(Zhmud 2012a, 122; 2012b, 241–43). However, certain parts of the
catalogue are very unlikely go back to Aristoxenus and we cannot be
certain that the inclusion of Alcmaeon was due to him (Huffman 2005,
297–99). Apart from this possibility regarding Aristoxenus, no
one earlier than Diogenes Laertius (ca. 200 AD) calls Alcmaeon a
Pythagorean. Aristotle wrote two books on the Pythagoreans but wrote a
separate book on Alcmaeon. Aristotle and Theophrastus refer to him a
number of times but never identify him as a Pythagorean, and this is
the practice of the doxographical tradition (see A4, 6, 8–10,
13–14, 17–18, in DK 24). Simplicius
(6th AD) reports that some have handed down the view that
Alcmaeon is a Pythagorean but notes that Aristotle denies it (De
An. 32.3). Most telling is Aristotle’s discussion of
Alcmaeon in Metaphysics book I (986a22 ff.). He notes a
similarity between Alcmaeon and a group of Pythagoreans in positing
opposites as the principles of things but expresses uncertainty as to
who influenced whom. Earlier scholars took this comparison of Alcmaeon
to the Pythagoreans as confirmation that he was a Pythagorean. Most
scholars of the last fifty years, however, have come to recognize that
Aristotle’s treatment of Alcmaeon here suggests the exact
opposite; it only makes sense to compare him with the Pythagoreans and
wonder who influenced whom, if he is not a Pythagorean (e.g., Guthrie
1962, 341: “Aristotle … expressly distinguishes him from
the Pythagoreans”). Certainly most of the opposites which are
mentioned as crucial to Alcmaeon do not appear in the Pythagorean
table of opposites, and there is no trace of the crucial Pythagorean
opposition between limit and unlimited in Alcmaeon. The overwhelming
majority of scholars since 1950 have accordingly regarded Alcmaeon as
a figure independent of the Pythagoreans (e.g., Guthrie 1962, 341;
Burkert 1972, 289; KRS 1983, 339; Lloyd 1991, 167; Kahn 2001; Riedweg
2005, 115; Primavesi 2012, 447. Zhmud [2012a, 121–124; 2014,
97–102] is the notable exception), although, as a fellow citizen
of Croton, he will have been familiar with their thought.

No issue concerning Alcmaeon has been more controversial than his
date. Some have sought to date him on the basis of his address to
Brotinus (e.g., Zhmud 2012a, 122). Brotinus’ dates are too
uncertain to be of much help, however. If he is Theano’s father
and Theano was Pythagoras’ wife, he could be a contemporary of
Pythagoras (570–490) or even older. If he is Theano’s
husband and she was a student of Pythagoras in his old age and thus
twenty in 490, Brotinus could have been born as late as 520. This
suggests that Brotinus could have been the addressee of the book any
time between 550 and 450 BCE. The center of controversy, however, has
been a sentence in the passage of Aristotle’s
Metaphysics discussed above:

Alcmaeon of Croton also seems to have thought along similar lines, and
either he took this theory over from them [i.e. the Pythagoreans] or
they from him. For in age Alcmaeon was in the old age of
Pythagoras, and his views were similar to theirs
(986a27–31).

The sentence in bold above is missing in one of the major manuscripts
and Alexander makes no mention of it in his commentary on the
Metaphysics. It does appear in the other two major
manuscripts and in Asclepius’ commentary. A number of scholars
have regarded it as a remark by a later commentator, which has crept
into the text (e.g., Ross 1924, 152; Burkert 1972, 29, n.60) and this
is the view of the most recent editor (Primavesi 2012, 447–8).
It is a surprising remark for Aristotle to make, since he only refers
to Pythagoras once elsewhere in all his extant writings and throughout
this passage of the Metaphysics refers to the Pythagoreans or
Italians in the plural. Other scholars regard the remark as genuine
(e.g., Wachtler 1896; Guthrie 1962, 341–3; Zhmud 2012a, 122).
Even if we accept the remark as genuine, the assertion that Alcmaeon
“was” (egeneto) in the old age of Pythagoras is
ambiguous. Does it mean that Alcmaeon was born in the old age of
Pythagoras, or that he lived (flourished?) in the old age of
Pythagoras? Diels emended the sentence to say that Alcmaeon was
“young” in the old age of Pythagoras and this emendation
is supported by a similar remark found in Iamblichus (VP
104). Although Diels accepted the text as Aristotelian, others have
seen the parallel with Iamblichus as evidence that it is a remark by a
later commentator and have pointed out that the report in Iamblichus
involves several chronological impossibilities (e.g., that Philolaus
was young in the old age of Pythagoras). Moreover, Diels’ text
suggests that the purpose of the remark was to show Alcmaeon’s
dependence on Pythagoras, which would show that the remark cannot be
due to Aristotle, who has just distinguished Alcmaeon from the
Pythagoreans and expressed doubts as to who influenced whom (Primavesi
2012, 447–8). Even if the remark is unlikely to go back to
Aristotle, his doubts about who influenced whom suggest that Alcmaeon
belonged to the late sixth or early fifth century (Schofield 2012,
156), which would argue against the late date of 440 adopted by
Mansfeld (2013, 78, n. 1). One group of scholars thus dates the
publication of Alcmaeon’s book to around 500 (Burkert 1972, 292;
Kirk, Raven, Schofield 1983, 339 [early 5th]; Zhmud 2012a,
122 [not later than 490]) so that he would have been born around 540.
Another group has him born around 510 so that his book would have been
published in 470 or later (Guthrie 1962, 358 [480–440 BCE];
Lloyd 1991, 168 [490–430 BCE]). In either case Alcmaeon probably
wrote before Empedocles, Anaxagoras, and Philolaus. He is either the
contemporary or the predecessor of Parmenides. Attempts to date him on
the basis of internal evidence alone, i.e. comparison of his doctrines
with those of other thinkers, have led to the widest divergence of
dates. Edelstein says that he may have lived in the late fifth century
(1942, 372), while Lebedev makes him active in the late 6th
(1993).

The ancient tradition assigns one book to Alcmaeon, which came to bear
the traditional title of Presocratic treatises, On Nature
(DK, A2), although this title probably does not go back to Alcmaeon
himself. Favorinus’ report that Alcmaeon was the first to write
such a treatise (DK, A1) is almost certainly wrong, since Anaximander
wrote before Alcmaeon. Theophrastus’ detailed report of
Alcmaeon’s account of the senses (DK, A5) and the fact that
Aristotle wrote a treatise in response to Alcmaeon (D.L. V. 25)
suggest that the book was available in the fourth century BCE. It is
unclear whether Alcmaeon wrote in the Doric dialect of Croton or in
the Ionic Greek of the first Presocratics (Burkert, 1972, 222, n. 21).
The report that an Alcimon of Croton was the first to write animal
fables might be a reference to a poet of a similar name. Fragment 5 in
DK (“It is easier to be on one’s guard against an enemy
than a friend.”) sounds very much like the moral of such a fable
(Gomperz 1953, 64–5). Diels and Kranz (=DK) identify five other
fragments of Alcmaeon (Frs. 1, 1a, 2, 3, 4) and arrange the testimonia
under 18 headings. Fragments 1a, 3 and 4, however, are really
testimonia which use language of a later date, although some of
Alcmaeon’s terminology is embedded in them. The three lines of
Fragment 1, which probably began the book, and the half line in
Fragment 2 are the only continuous texts of Alcmaeon. Another brief
fragment/testimonium should be added to the material in DK: “the
earth is the mother of plants and the sun their father”
(Nicolaus Damascenus, De plantis I 2.44; see Kirk 1956 and
Lebedev 1993). There is also the possibility that Fr. 125 of the
Spartan poet Alcman (“Experience is the beginning of
learning.”) should, in fact, be assigned to Alcmaeon (Lanza
1965; Barnes 1982, 610).

Concerning things that are not perceptible [concerning mortal things]
the gods have clarity, but insofar as it is possible for human beings
to judge (tekmairesthai) … (DK, B1)

Such skepticism about human knowledge is characteristic of one strand
of early Greek thought. Both Alcmaeon’s predecessors (e.g.,
Xenophanes B34) and his successors (e.g., Philolaus B6) made similar
contrasts between divine and human knowledge, but in Alcmaeon’s
case, as in these other cases, we do not have enough evidence to be
sure what he intended. Most of the subjects that Alcmaeon went on to
discuss in his book could not be settled by a direct appeal to sense
perception (e.g., the functioning of the senses, the balance of
opposites in the healthy body, the immortality of the soul). In this
sense he was dealing largely with what is “not
perceptible” (aphanes). Alcmaeon is decidedly not an
extreme skeptic, however, in that he is willing to assign clear
understanding about such things to the gods and by implication admits
that even humans have clear understanding of what is directly
perceptible. Moreover, while humans cannot attain clarity about what
cannot be perceived, Alcmaeon thinks that they can make reasonable
judgments from the signs that are presented to them by sensation
(tekmairesthai). He thus takes the stance of the scientist
who draws inferences from what can be perceived, and he implicitly
rejects the claims of those who base their account of the world on the
certainty of a divine revelation (e.g., Pythagoras, Parmenides
B1).

There are difficulties with the text of Fr. 1, which make its
interpretation problematic. Some scholars exclude the material in
brackets above because it is hard to see how to connect it to what
precedes (e.g., Wachtler 1896), while others keep the material and
suppose that we are to understand an “and” coordinating
the phrase in brackets with what precedes it (e.g., DK 1952). Recently
Gemelli Marciano (2007, 18–22) has suggested that the material
in brackets above should be kept but made dependent on the immediately
preceding phrase rather than coordinated with it, so that the fragment
would read:

Concerning things that are not perceptible concerning mortals the gods
have clarity, but insofar as it is possible for human beings to judge
… (DK, B1)

If we regard Alcmaeon as primarily a doctor or medical thinker, rather
than as a cosmologist, “things that are not perceptible
concerning mortals” is likely to refer to the interior of the
body and hidden diseases. Passages in the Greek medical writings of
the fifth century provide clear parallels for the difficulty of
knowing about the interior of the body and invisible maladies (Gemelli
Marciano 2007, 20–21). On this reading Fr.1 is addressed to
medical students. Parallels with medical treatises suggest that, after
first raising difficulties about medical knowledge in these matters,
Alcmaeon may have gone on to assert that these difficulties can be
overcome with the proper teaching, the teaching that followed in his
book. If this is the correct context in which to read the fragment, it
is not so much about the limits of understanding as the success of
medical teaching in overcoming apparent limits.

According to Theophrastus, Alcmaeon was the first Greek thinker to
distinguish between sense perception and understanding and to use this
distinction to separate animals, which only have sense perception,
from humans, who have both sense perception and understanding (DK,
B1a, A5). Alcmaeon is also the first to argue that the brain is the
central organ of sensation and thought (DK, A5, A8, A10). There is no
explicit evidence, however, as to what Alcmaeon meant by
understanding. The word translated as understanding here is
suniêmi, which in its earliest uses means “to
bring together,” so that it is possible that Alcmaeon simply
meant that humans are able to bring the information provided by the
senses together in a way that animals cannot (Solmsen 1961, 151).
Animals have brains too, however, and thus might appear to be able to
carry out the simple correlation of the evidence from the various
senses, whereas the human ability to make inferences and judgments
(DK, B1) appears to be a more plausible candidate for the distinctive
activity of human intelligence. It is possible that we should use a
passage in Plato’s Phaedo (96a-b = A11) to explicate
further Alcmaeon’s epistemology. The passage is part of
Socrates’ report of his early infatuation with natural science
and with questions such as whether it is the blood, or air, or fire
with which we think. He also reports the view that it is the brain
that furnishes the sensations of hearing, sight, and smell. This
corresponds very well with Alcmaeon’s view of the brain as the
central sensory organ and, although Alcmaeon is not mentioned by name,
many scholars think that Plato must be referring to him here. Socrates
connects this view of the brain with an empiricist epistemology, which
Aristotle will later adopt (Posterior Analytics 100a3 ff.).
This epistemology involves three steps: first, the brain provides the
sensations of hearing, sight and smell, then, memory and opinion arise
from these, and finally, when memory and opinion achieve fixity,
knowledge arises. Some scholars suppose that this entire epistemology
is Alcmaeon’s (e.g., Barnes 1982, 149 ff.), while others more
cautiously note that we only have explicit evidence that Alcmaeon took
the first step (e.g., Vlastos 1970, 47, n.8).

Alcmaeon’s empiricism has sometimes been thought to have arisen
from his experience as a practicing physician (Guthrie 1962). He has
also been hailed as the first to use dissection, but this is based on
a hasty reading of the evidence. Calcidius, in his Latin commentary on
Plato’s Timaeus, praises Alcmaeon, along with
Callisthenes and Herophilus, for having brought many things to light
about the nature of the eye (DK, A10). Most of what Calcidius goes on
to describe, however, are the discoveries of Herophilus some two
centuries after Alcmaeon (Lloyd 1975, Mansfeld 1975, Solmsen 1961).
The only conclusions we can reasonably draw about Alcmaeon from the
passage are that he excised the eyeball of an animal and observed
poroi (channels, i.e. the optic nerve) leading from the eye
in the direction of the brain (Lloyd 1975). Theophrastus’
account of Alcmaeon’s theory of sensation implies that he
thought that there were such channels leading from each of the senses
to the brain:

All the senses are connected in some way with the brain. As a result,
they are incapacitated when it is disturbed or changes its place, for
it then stops the channels, through which the senses operate. (DK, A5)

There is no evidence, however, that Alcmaeon dissected the eye itself
or that he dissected the skull in order to trace the optic nerve all
the way to the brain. Alcmaeon’s account of the other senses,
far from suggesting that he carried out dissections in order to
explain their function, implies that he did not (Lloyd 1975; for a
partial critique of Lloyd see Perilli 2001). Alcmaeon’s
conclusion that all of the senses are connected to the brain may have
been drawn from nothing more that the excision of the eye and the
general observation that the sense organs for sight, hearing, smell,
and taste are located on the head and appear connected to passages
which lead inward towards the brain (Gomperz 1953, 69). It is striking
in this regard that Alcmaeon gave no account of touch (DK, A5), which
is the only sense not specifically tied to the head. It would be a
serious mistake then to say that Alcmaeon discovered dissection or
that he was the father of anatomy, since there is no evidence that he
used dissection systematically or even that he did more than excise a
single eyeball.

Theophrastus says that Alcmaeon did not explain sensation by the
principle of like to like (i.e. by the likeness between the sense
organ and what is perceived), a principle which was used by many early
Greek thinkers (e.g., Empedocles). Unfortunately he gives no general
account of how Alcmaeon did think sensation worked (DK, A5). Alcmaeon
explained each of the individual senses with the exception of touch,
but these accounts are fairly rudimentary. He regarded the eye as
composed of water and fire and vision as taking place when what is
seen is reflected in the gleaming and translucent part of the eye.
Hearing arises when an external sound is first transmitted to the
outer ear and then picked up by the empty space (kenon) in
the inner ear, which transmits it to the brain. Taste occurs through
the tongue, which being warm and soft dissolves things with its heat
and, because of its loose texture, receives and transmits the
sensation. Smell is the simplest of all. It occurs “at the same
time as we breathe in, thus bringing the breath to the brain”
(DK, A5).

Alcmaeon developed the first argument for the immortality of the soul,
but the testimonia concerning it differ slightly from one another, and
it appears to have been taken over and developed by Plato, so that it
is very hard to determine exactly how to reconstruct Alcmaeon’s
own argument. Barnes (1982, 116–120) and Hankinson (1998,
30–3) provide the most insightful analysis. Alcmaeon appears to
have started from the assumption that the soul is always in motion. At
one extreme we might suppose that Alcmaeon only developed the simple
argument from analogy, which Aristotle assigns to him (De An.
405a29). The soul is like the heavenly bodies, which Alcmaeon regarded
as divine and immortal (DK, A1, A12), in being always in motion, so it
is also like them in being immortal. This is clearly fallacious, since
it assumes that things that are alike in one respect will be alike in
all others. The version in the doxographical tradition is more
sophisticated (DK, A12). Alcmaeon thought that the soul moved itself
in continual motion and was therefore immortal and like to the divine.
The similarity to the divine is not part of the inference here but
simply an illustrative comparison. However, Mansfeld has recently
pointed out that the doxographical report in Aetius is just a
paraphrase of Aristotle’s earlier report with the significant
addition that the soul is self-moving. Examination of the context in
Aetius shows that the self-motion of the soul, which is attested
independently for Plato and Xenocrates, was projected back on
Pythagoras and Thales, who are very unlikely to have held such a view.
This context and Aristotle’s failure to assign self-motion to
Alcmaeon makes it likely that the same projection occured in the case
of Alcmaeon, who thus is likely to have assigned continual motion but
not self motion to the soul (Mansfeld 2014b). The core of the simpler
argument is the necessary truth that what is always in motion must be
immortal. This is the assumption from which Plato starts his argument
for the immortality of the soul at Phaedrus 245c, but how
much of Plato’s analysis of what is always in motion can be
assigned to Alcmaeon? Plato makes no mention of Alcmaeon in the
passage. There are still serious questions for Alcmaeon, even on the
more sophisticated version of the argument. We might well recognize
that things with souls, i.e. things that are alive, are able to move
themselves, and conclude that it is souls that bring this motion
about. We might also conclude that the soul, as what moves something
else, must be in motion itself (the synonymy principle of causation).
But why did Alcmaeon suppose that the soul must be always in motion?
(Hankinson [1998, 32] provides two possible answers and discusses the
difficulties with them.) Horn argues that there is no obvious meaning
to the idea that the human soul is in continual motion so that
Alcmaeon must be talking about a world soul, which has the continual
motion of the heavens (2005, 157–8). However, Mansfeld rightly
argues that Aristotle’s report on Alcmaeon’s view of the
soul is clearly about the human soul; since the soul being discussed
is said to be similar to the heavenly motions it has to be distinct
from them (2014a). Finally, what sort of motion is being ascribed to
souls? The natural assumption might be that the soul’s motion is
thinking, but, at this early point in Greek thought, Alcmaeon was more
likely to have thought that, if the soul is going to cause motion in
space, it too must be in locomotion. Plato describes the soul as
composed of two circles with contrary motions, which imitate the
contrary motions of the fixed stars and the planets, so that the soul
becomes a sort of orrery in the head (Timaeus 44d). It has
been suggested that this image is borrowed from Alcmaeon (Barnes 1982,
118; Skemp 1942, 36 ff.).

In Fragment 2, Alcmaeon is reported to have said that:

Human beings perish because they are not able to join their beginning
to their end.

At first sight, this assertion might appear to conflict with
Alcmaeon’s belief that the soul is immortal. It seems likely,
however, that Alcmaeon distinguished between human beings as
individual bodies, which do perish, and as souls, which do not (Barnes
1982, 115). There is no evidence about what Alcmaeon thought happened
to the soul, when the body perished, however. Did he believe in
reincarnation as the Pythagoreans did? No ancient source associates
Alcmaeon with reincarnation and his sharp distinction between animals
and human beings may suggest that he did not believe in it (Guthrie
1962: 354). He might have thought that the soul joined other divine
beings in the heavens. The point of Fragment 2 may be that, whereas
the heavenly bodies do join their beginnings to their ends in circular
motion, humans are not able to join their end in old age to their
beginning in childhood, i.e. human life does not have a cyclical
structure. We might even suppose that the soul tries to impose such a
structure on the body from its own circular motion but ultimately
fails (Guthrie 1962, 353).

Alcmaeon said that the equality (isonomia) of the powers
(wet, dry, cold, hot, bitter, sweet, etc.) maintains health but that
monarchy among them produces disease.

This is, in fact, not a fragment but a testimonium and much of the
language comes from the doxographical tradition rather than Alcmaeon.
The report goes on to say that Alcmaeon thought that disease arose
because of an excess of heat or cold, which in turn arose because of
an excess or deficiency in nutrition. Disease is said to arise in the
blood, the marrow, or the brain. It can also be caused by external
factors such as the water, the locality, toil, or violence. The idea
that health depends on a balance of opposed factors in the body is a
commonplace in Greek medical writers. Although Alcmaeon is the
earliest figure to whom such a conception of health is attributed, it
may well be that he is not presenting an original thesis but rather
drawing on the earlier medical tradition in Croton. Perhaps what is
distinctive to Alcmaeon is the use of the specific political metaphor
and most scholars (e.g., Sassi 2007, 198; Jouanna 1999, 327) agree
that the political terminology (isonomia, monarchia)
goes back to him. Indeed, these terms are not found elsewhere in the
Greek medical tradition. Just as Anaximander explained the order of
the cosmos in terms of justice in the city-state, so Alcmaeon used a
political metaphor to explain the order of the human body. It is
commonly recognized that isonomia (equality) is not a
specific form of government but rather a concept of political equality
in terms of which forms of government are evaluated (Ostwald 1969,
108; Meier 1990, 162 calls it a “yardstick”, Vlastos 1981,
173–74 a “banner”). Its primary application is to
democracies (Herodotus III.80) but it is also applied to moderate
oligarchies that have democratic features (Thucydides III.
62.3–4). Although a significant number of scholars argue that
there is a purely aristocratic application for isonomia as
the equality of aristocratic peers in opposition to a tyrant (e.g.,
Raaflaub 2004: 95; Zhmud 2012a: 358), one of the most noted early
adherents of this view later abandoned it (Ehrenberg 1956: 67) and it
appears more likely that the term isonomia originated with
the radical democracy which emerged in Athens in the late sixth
century and was only applied in a secondary sense to moderate
oligarchies (Vlastos 1973, 175–7; Ostwald 1969, 99–106).
Is Alcmaeon’s use of the term simply descriptive of the equality
of powers that is necessary for the healthy body, or does his use of
the term to describe health suggest that he was in sympathy with
radical democracy (Vlastos 1953, 363)? We simply have no direct
evidence for Alcmaeon’s political views. However, Aristotle
emphasizes that Alcmaeon posited an indefinite number of opposites as
active in the human body in contrast to the Pythagoreans who specified
ten pairs (see 4.2 below), which suggests that Alcmaeon’s
“body” politic was not an oligarchy with a numerically
defined group of peers but rather a democracy which gave equality to
the full range of opposites. Mansfeld has recently argued that
scholars are wrong to ascribe the key terms isonomia and
monarchia to Alcmaeon (Mansfeld 2014a). Such a metaphorical
use of isonomia is unparalleled at this early date and is
much more likely to have been introduced later in the doxographical
tradition. Moreover, monarchia may have been introduced by a
doxographer familiar with its use in the famous debate on
constitutions in Herodotus (III 80–3), where isonomia
also appears (III 80). Mansfeld concludes that this origin of the
terms from the doxography is more likely than assuming influence on
Alcmaeon from the reforms of Cleisthenes. The difficulty with
Mansfeld’s approach is that the striking thing about the report
on Alcmaeon is preceisely the political metaphor and it seems more
plausible that his views were introduced into the doxography because
of that metaphor than that his views were typical Greek views on
disease and the metaphor only arose as an artefact of the
doxographical tradition. If he did introduce the political metaphor
then it is as probable as not that he used the terms ascribed to him,
especially since both appear only a little later in Herodotus,
although not with a metaphorical sense.

Alcmaeon is the first to raise a series of questions in human and
animal physiology that later become stock problems, which every
thinker tries to address. He thus sets the initial agenda for Greek
physiology (Longrigg 1993, 54–7; Lloyd 1966, 322 ff.). He said
that sleep is produced by the withdrawal of the blood away from the
surface of the body to the larger (“blood-flowing”)
vessels and that we awake when the blood diffuses throughout the body
again (DK, A18). Death occurs when the blood withdraws entirely.
Hippocratic writers (Epid. VI 5.15) and Aristotle
(H.A. 521a15) both seem to have adopted Alcmaeon’s
account of sleep. It is very unlikely, however, that Alcmaeon
distinguished between veins (the “blood-flowing vessels”)
and arteries, as some have claimed. It is more likely that he simply
distinguished between larger more interior blood vessels as opposed to
smaller ones close to the surface (Lloyd 1991, 177). He probably
argued that human seed was drawn from the brain (DK, A13). Contrary to
a popular Greek view, which regarded the father alone as providing
seed, a view that would be followed by Aristotle (Lloyd 1983, 86 ff.),
Alcmaeon may have argued that both parents contribute seed (DK, A13)
and that the child takes the sex of the parent who contributes the
most seed (DK, A14). It has recently been suggested, however, that our
sole source for these views (Censorinus) is mistaken and that, while
Alcmaeon thought that both the male and female contributed to the
child, only the male contributed seed (Leitao 2012: 278–79), the
female contributing menses. According to one report, Alcmaeon thought
that the head was the first part of the embryo to develop, although
another report has him confessing that he did not have definite
knowledge in this area, because no one is able to perceive what is
formed first in the infant (DK, A13). These reports are not
inconsistent and conform to the epistemology with which Alcmaeon began
his book. It is plausible to suppose that he regarded the development
of the embryo as one of the imperceptibles about which we can have no
certain knowledge. On the other hand, he may have regarded it as a
reasonable inference that the part of the body which controls it in
life, i.e., the brain, developed first in the womb. Dissection is of
obvious relevance to the debate about the development of the embryo,
and Alcmaeon’s failure to appeal to dissection of animals in
this case is further evidence that he did not employ it as a regular
method (Lloyd 1979, 163). Alcmaeon studied not just humans but also
animals and plants. He gave an explanation of the sterility of mules
(DK, B3) and, if we can believe Aristotle, thought that goats breathed
through their ears (DK, A7). More significantly, he used analogies
with animals and plants in developing his accounts of human
physiology. Thus, the pubic hair that develops when human males are
about to produce seed for the first time at age fourteen is analogous
to the flowering of plants before they produce seed (DK, A15); milk in
mammals is analogous to egg white in birds (DK, A16). The infant in
the womb absorbs nutrients through its entire body, like a sponge,
although another report suggests that the embryo already feeds through
its mouth (DK, A17). However, the text of the latter report should
perhaps be amended from stomati [mouth] to
sômati [body], thus removing the contradiction
(Olivieri 1919, 34). Analogies such as these will become a staple item
in later Greek biological treatises, but Alcmaeon is one of the
earliest figures in this tradition.

As indicated in section 1 above, there is considerable controversy as
to whether and to what extent Alcmaeon was a typical Presocratic
cosmologist. Certainly the evidence for his cosmology is meager. There
are three references to his astronomical theory (DK, A4). He is
reported to have recognized that the planets have a motion from west
to east opposite to the motion of the fixed stars. Some doubt that
such knowledge was available at the beginning of the fifth century
(Dicks 1970, 75). Others suggest that Anaximenes, in the second half
of the sixth century, had already distinguished between the fixed
stars, which are nailed to the ice-like vault of the sky, and planets
which float on the air like leaves (DK13A7; Burkert 1972, 311).
Alcmaeon’s belief that the sun is flat is another possible
connection to Anaximenes, who said that the sun was flat like a leaf
(DK13A15). Finally, another similarity to Ionian astronomy is found in
Alcmaeon’s agreement with Heraclitus that lunar eclipses were to
be explained by the turning of a bowl-shaped moon. One might have
expected, however, that the moon would be flat like the sun (West
1971, 175).

Did Alcmaeon present a cosmogony or cosmology in terms of the
interaction of pairs of opposites? Such a cosmology could be seen as
yet another connection to earlier speculation in Ionia, since
Anaximander’s cosmos is based on the “justice”
established between conflicting opposites (DK12B1). Heraclitus is also
a possible influence on Alcmaeon, since he seems to envisage an
endless process of opposites turning into one another such as is
proposed for Alcmaeon (Mansfeld 2014a, 91–2). Aristotle provides
the primary evidence for such a cosmology in Alcmaeon
(Metaph. 986a22 ff. = A3), but he compares Alcmaeon not to
the Ionians but to a group of Pythagoreans who proposed a table of ten
pairs of opposites. Alcmaeon agrees with these Pythagoreans in
regarding the opposites as principles of things. Aristotle complains,
however, that Alcmaeon did not arrive at a definite set of opposites
but spoke haphazardly of white, black, sweet, bitter, good, bad,
large, and small, and only threw in vague comments about the remaining
opposites. It may well be that Alcmaeon’s primary discussion of
opposites was in relation to his account of the human body (DK, B4;
see the discussion of his medical theories above). Aristotle’s
language supports this suggestion to some extent, when he summarizes
Alcmaeon’s view as that “the majority of human
things (tôn anthrôpinôn) are in
pairs” (Metaph. 986a31). Isocrates (DK, A3) says that
Alcmaeon, in contrast to Empedocles, who postulated four elements,
said that there were only two, and, according to a heterodox view,
Alcmaeon posited fire and earth as basic elements (Lebedev 1993). Most
scholars follow Aristotle, however, in supposing that Alcmaeon thought
that the human body and perhaps the cosmos is constituted from the
balance of an indefinite number of opposites. Some have seen
Alcmaeon’s unwillingness to adopt a fixed set of opposites as a
virtue and a further sign of his empiricism, which is willing to
accept that the world is less tidy than theoretical constructs, such
as the Pythagorean table of opposites, would suggest (Guthrie 1962,
346).

Alcmaeon has been somewhat neglected in recent scholarship on early
Greek philosophy (e.g., he hardly appears in Curd and Graham 2008,
Long 1999 and Taylor 1997, the most recent surveys of the subject, but
both Guthrie 1962 and now Zhmud 2012a and 2014 stress his importance).
There would appear to be several reasons for this neglect. First, what
remains of Alcmaeon’s book has little to say on the metaphysical
questions about the first principles of the cosmos and about being,
which have dominated recent scholarship on the Presocratics. Second,
doubts about his date and about the focus of his investigations have
made it difficult to place him in the development of early Greek
thought. Finally, a more accurate appreciation of his use of
dissection has deflated some of the hyperbolic claims in earlier
scholarship about his originality. The extent of his originality and
the importance of his influence depend to a degree on his dating. An
extremely late dating for his activity (after 450 BCE) makes him
appear to espouse the typical views of the age rather than to break
new ground. If he was active in the early fifth century, his views are
much more original. That Aristotle wrote a separate treatise in
response to Alcmaeon argues in favor of his originality. He should
probably be regarded as a pioneer in applying a political metaphor to
the balance of opposites that constitute the healthy human body. The
range of his work in biology is remarkable for the early fifth century
and he may have initiated a physiological emphasis in Greek philosophy
which was not present in Ionian philosophers, such as Anaximander and
Anaximenes, and set the agenda in this area for later Presocratics
(Zhmud 2012a, 366). It is sometimes said that his conception of
poroi (channels), which connect the sense organs to the
brain, influenced Empedocles’ theory of poroi, but the
theories may share no more than the name. In Empedocles, all materials
have pores in them, which determine whether they mix well with other
objects. Sense organs also have pores, but these function not to
connect the sense organ to the seat of intelligence (which for
Empedocles is the heart) but to determine whether the sense organ can
receive the effluences that are poured forth by external objects
(Solmsen 1961, 157; Wright 1981, 230). Alcmaeon’s influence was
significant in three final ways: 1) His identification of the brain as
the seat of human intelligence influenced Philolaus (DK, B13), the
Hippocratic Treatise, On the Sacred Disease, and Plato
(Timaeus 44d), although a number of thinkers including
Empedocles and Aristotle continued to regard the heart as the seat of
perception and intelligence. 2) His empiricist epistemology may lie
behind important passages in Plato (Phaedo 96b) and Aristotle
(Posterior Analytics 100a). 3) He developed the first
argument for the immortality of the soul, which may have influenced
Plato’s argument in the Phaedrus (245c ff.).

Texts and Commentaries

Diels, H. and W. Kranz, 1952, Die Fragmente der
Vorsokratiker (in three volumes), 6th edition, Dublin
and Zürich: Weidmann, Volume 1, Chapter 24, 210–216. Greek
texts of the fragments and testimonia with translations in German.
Referred to as [DK]. The testimonia for each author are indicated by
an A and a number. So A5 is the fifth testimonia about Alcmaeon listed
in DK. The B annotations refer to actual fragments of Alcmaeon in DK
as opposed to the testimonia, second hand reports, etc., constituting
the A annotations.